Income Taxes - Unrecognized tax benefits activity (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits [Roll Forward]    
Balance-beginning of year $ 29,523 $ 0
Acquisitions 0 29,701
Increases based on tax positions of the current year 1,005 795
Decreases due to lapse of statute (236) 0
Increases based on tax positions of the prior years 1,963 0
Decreases based on tax positions of the prior years (664) 0
Currency translation adjustments (1,427) (973)
Balance-end of year $ 30,164 $ 29,523